Smoothed image generating device, abnormality determining device, and smoothed image generating method

1. A smoothed image generating device which generates smoothed image data, in which brightness is smoothed, from imaging data which an image capturing device has obtained by capturing a subject having uniform brightness, the smoothed image generating device comprising: a reduced-size divided data generating section which generates reduced-size divided data by extracting some of a plurality of regions from divided data, the divided data being obtained by dividing, into the plurality of regions, brightness data obtained by extracting brightness information from the imaging data; a smoothing processing section which generates smoothed reduced-size divided data by carrying out a smoothing process with respect to the reduced-size divided data; and a smoothed image generating section which expands the smoothed reduced-size divided data into smoothed image data, which is identical in size to the divided data, and interpolates brightness between regions in which the regions constituting the smoothed reduced-size divided data are not arranged.

2. The smoothed image generating device as set forth in claim 1 , wherein the reduced-size divided data generating section generates the reduced-size divided data by extracting every second region in a horizontal direction and in a vertical direction, out of the plurality of regions constituting the divided data.

3. The smoothed image generating device as set forth in claim 1 , wherein the reduced-size divided data generating section generates the reduced-size divided data by (i) dividing the divided data into three types of regions, a first one of which includes four regions including respective corners, a second one of which includes regions constituting an outer periphery, and a third one of which includes the other region, and (ii) extracting the some of the plurality of regions, constituting the divided data, by methods which are different between the three types of regions.

4. A smoothed image generating device which generates smoothed image data, in which brightness is smoothed, from imaging data which an image capturing device has obtained by capturing a subject having uniform brightness, the smoothed image generating device comprising: a reduced-size divided data generating section which generates reduced-size divided data by extracting some of a plurality of regions from divided data, the divided data being obtained by dividing, into the plurality of regions, brightness data obtained by extracting brightness information from the imaging data; a smoothing processing section which generates smoothed reduced-size divided data by carrying out a smoothing process with respect to the reduced-size divided data; and a smoothed image generating section which generates smoothed image data, which is identical in size to the divided data, by interpolating between a plurality of regions constituting the smoothed reduced-size divided data, the smoothing processing section carrying out the smoothing process with use of a smoothing filter which causes the smoothing process to be carried out for each given range, and the smoothing process being a process in which the smoothing processing section (i) calculates a predictive value that predicts a value of brightness indicated by a region sandwiched between regions located at respective ends of the each given range, with use of values of brightness indicated by the respective regions located at the respective ends of the each given range, out of regions included in the each given range, and (ii) replaces, with the predictive value, the value of the brightness indicated by the region in a case where the value of the brightness indicated by the region is lower than the predictive value.

5. The smoothed image generating device as set forth in claim 4 , wherein: the each given range includes vertically or horizontally arranged regions; and the smoothing processing section uses the smoothing filter which causes the predictive value to be calculated by linear interpolation with use of the values of the brightness indicated by the respective regions located at the respective ends of the each given range.

6. The smoothed image generating device as set forth in claim 1 , wherein the smoothed image generating section generates the smoothed image data by (i) arranging, at respective locations corresponding to those in the divided data, the plurality of regions constituting the smoothed reduced-size divided data and (ii) setting brightness, calculated by linear interpolation, in each of blanks located between arranged regions.

7. An abnormality determining device comprising: a smoothed image generating device recited in claim 1 ; and an abnormality determining section which compares smoothed image data with divided data, each of which is generated by the smoothed image generating device, and determines whether or not an image capturing device has an abnormality.

8. A smoothed image generating method of generating smoothed image data, in which brightness is smoothed, from imaging data which an image capturing device has obtained by capturing a subject having uniform brightness, the method comprising: a reduced-size divided data generating step of generating reduced-size divided data by extracting some of a plurality of regions from divided data, the divided data being generated with use of brightness data obtained by extracting brightness information from the imaging data and being constituted by the plurality of regions each of which indicates adjusted brightness; a smoothing processing step of generating smoothed reduced-size divided data, in which entire brightness is smoothed, with use of a smoothing filter which causes a smoothing process to be carried out with respect to the reduced-size divided data; and a smoothed image generating step of expanding the smoothed reduced-size divided data into smoothed image data, which is identical in size to the divided data, and interpolating brightness between regions in which the regions constituting the smoothed reduced-size divided data are not arranged.